Student Loan Calculator
Estimate payments, total cost, and payoff timeline for your student loans.
Yearly Amortization Schedule
| Year | Interest Paid | Principal Paid | Remaining Balance |
|---|
What is a Student Loan Calculator?
A student loan calculator shows the true cost of borrowing for college or graduate school. Enter your balance, rate, and term to see your monthly payment, total interest, and payoff date — then model extra payments to see how much an extra $50 or $100 a month saves. Everything runs locally in your browser.
How to Use This Calculator
- Enter your loan balance (or the total you expect to borrow) and annual interest rate.
- Enter the term in years — the standard federal plan is 10 years; extended plans run 20 or 25.
- Optionally add an extra monthly payment to compare strategies.
- Click Calculate for your payment, total interest, payoff date, and yearly amortization schedule.
Have several loans? Run the calculator once per loan. Planning ahead? Estimate costs with our college cost calculator.
The Student Loan Payment Formula
Fixed-rate student loans — including all federal Direct Loans — use the standard amortization formula to set one level monthly payment:
M = P × r(1 + r)ⁿ / ((1 + r)ⁿ − 1)
- M — the monthly payment.
- P — the principal: your outstanding balance when repayment begins.
- r — the monthly interest rate: the annual rate ÷ 12 as a decimal. A 5.5% rate becomes 0.055 ÷ 12 ≈ 0.0045833.
- n — the number of monthly payments: years × 12. A 10-year term has 120 payments.
Total interest is everything you repay beyond the principal. Federal loans accrue interest daily, while this calculator compounds monthly like most lender quotes, so real totals may differ by a few dollars.
Worked Example: $30,000 at 5.5% for 10 Years
Suppose you owe $30,000 at a 5.5% fixed rate on the standard 10-year plan. The variables are P = 30,000, r = 0.055 ÷ 12 ≈ 0.0045833, and n = 120. Plugging them in:
M = 30,000 × 0.0045833(1.0045833)¹²⁰ / ((1.0045833)¹²⁰ − 1) = $325.58
You make 120 payments of $325.58 (the last is slightly smaller), repaying $39,069.46 in total — $9,069.46 of it interest. In month one, $137.50 covers interest and only $188.08 reduces principal. Adding $100 extra per month pays the loan off in 86 months — nearly 3 years early — and saves $2,753.32 in interest.
Student Loan Payment Comparison Table
Payments and total interest for common balances and rates on a 10-year term:
| Loan Balance | Interest Rate | Monthly Payment | Total Interest | Total Repaid |
|---|---|---|---|---|
| $20,000 | 4.0% | $202.49 | $4,298.83 | $24,298.83 |
| $20,000 | 5.5% | $217.05 | $6,046.31 | $26,046.31 |
| $20,000 | 7.0% | $232.22 | $7,866.04 | $27,866.04 |
| $30,000 | 4.0% | $303.74 | $6,448.25 | $36,448.25 |
| $30,000 | 5.5% | $325.58 | $9,069.46 | $39,069.46 |
| $30,000 | 7.0% | $348.33 | $11,799.05 | $41,799.05 |
| $50,000 | 4.0% | $506.23 | $10,747.08 | $60,747.08 |
| $50,000 | 5.5% | $542.63 | $15,115.77 | $65,115.77 |
| $50,000 | 7.0% | $580.54 | $19,665.09 | $69,665.09 |
10 Years vs. 20 Years: The Payment–Interest Trade-off
Stretching the term lowers the monthly bill but sharply raises the lifetime cost. For a $30,000 loan at 5.5%:
| Repayment Term | Monthly Payment | Total Interest | Total Repaid |
|---|---|---|---|
| 10 years | $325.58 | $9,069.46 | $39,069.46 |
| 20 years | $206.37 | $19,527.89 | $49,527.89 |
The 20-year term frees up $119.21 per month but costs an extra $10,458.43 in interest — over a third of the original balance. Choose the shortest term you can comfortably afford and pay extra in good months.
Federal vs. Private Student Loans
Federal Direct Loans carry fixed rates set by Congress and include protections private lenders rarely match: income-driven repayment, deferment and forbearance, and forgiveness programs such as Public Service Loan Forgiveness. Federal subsidized loans (for undergraduates with financial need) accrue no interest while you are in school at least half-time, during the grace period, or during deferment; unsubsidized loans accrue interest from the day they are disbursed.
Private loans from banks and online lenders are credit-based, carry fixed or variable rates, and generally lack income-driven plans and federal forgiveness. Compare both paths with our loan calculator before borrowing.
Income-Driven Repayment, Deferment, and Grace Periods
If the standard payment is unaffordable, federal income-driven repayment (IDR) plans cap the monthly bill at roughly 10% to 20% of discretionary income and forgive any balance left after 20 or 25 years of qualifying payments — but slower principal reduction usually means more total interest.
Deferment and forbearance both pause payments: in deferment only unsubsidized loans accrue interest; in forbearance it accrues on all loans, and unpaid interest is typically capitalized (added to your principal) afterward. Most federal loans also allow a six-month grace period after you leave school or drop below half-time; unsubsidized interest still accrues — roughly $825 on a $30,000 balance at 5.5%.
Should You Refinance Your Student Loans?
Refinancing replaces existing loans with a new private loan, ideally at a lower rate. Moving $30,000 from 7% to 5% on a 10-year term drops the payment from $348.33 to $318.20 and saves $3,615.47 in interest. The catch: refinancing federal loans permanently gives up income-driven repayment, forgiveness, and federal deferment protections, so it fits best for private loans or borrowers who will never need those safety nets.
Frequently Asked Questions
How is the monthly payment calculated?
Payments use the standard amortization formula M = P × r(1 + r)ⁿ / ((1 + r)ⁿ − 1), where P is your balance, r is the monthly rate (annual rate ÷ 12), and n is the number of months. A $30,000 loan at 5.5% for 10 years gives $325.58 per month.
Can I pay off my student loans early?
Yes. Federal and most private student loans have no prepayment penalty, and extra payments go straight to principal. Adding $100 a month to a $30,000 loan at 5.5% saves about $2,753 in interest and pays it off 34 months early.
What is the difference between subsidized and unsubsidized loans?
Subsidized federal loans do not accrue interest while you are in school at least half-time, during the six-month grace period, or during deferment — the government covers it. Unsubsidized loans accrue interest from disbursement, and unpaid interest is capitalized when repayment starts.
Does interest accrue during deferment or forbearance?
In deferment, interest accrues only on unsubsidized loans; in forbearance, on all loans. Unpaid interest is typically capitalized — added to principal — when the pause ends.
How long is the grace period on student loans?
Most federal Direct Loans allow six months after you graduate, leave school, or drop below half-time before payments are due. Interest still accrues on unsubsidized loans — about $825 on a $30,000 balance at 5.5% over six months.
How does income-driven repayment work?
Federal income-driven plans cap your payment at roughly 10% to 20% of discretionary income and forgive any balance remaining after 20 or 25 years of qualifying payments. You recertify income annually, and lower payments usually mean more total interest.
Should I refinance my student loans?
Refinancing can cut your rate — moving $30,000 from 7% to 5% over 10 years saves about $3,615 in interest — but refinancing federal loans into a private loan permanently forfeits income-driven repayment, forgiveness eligibility, and federal deferment protections. It fits best for private loans or borrowers who never need those safety nets.